Dynamics of organic carbon and total nitrogen under different types of land use in Napahai marsh wetland,northwest Yunnan was studied with the sequential coring and in-situ exposure method.The results show that soil organic carbon and total N varied significantly both vertically and horizontally.The content of organic matter was 110.67 g kg^-1 in the primary marsh soil,85.30 g kg^-1 in the swampy meadow topsoil and only 22.66 g kg^-1 in the deep soil layer,and decreased horizontally from primary marsh to swampy meadow,meadow and to cropland by 22.92%~69.64%.Total N followed organic matter in the same trend in spatial distribution,showing a significant correlation coefficient vert ically (r_(top)=0.93,r_(deep)=0.96).But it had a low correlation coefficient horizontally with NH₄⁺-N(r=-0.74) and NO₃^--N (r=-0.65).Besides,a significantly negative correlation was observed between NH₄⁺-N (NO₃^--N) and hydrolysable N (r=-0.81,r=-0.76).The C/N was high (average 23.69) in the primary marsh,showing that primary marsh in Napahai wetland had low mineralization rate,a high nitro-gen accumulation rate and a carbon fixation rate,which also explains that soil organic carbon and total N in Napahai wetland are degrading with human disturbances.